1. Field of the Invention
This invention relates to a press driven by an electric motor through reduction gearing and particularly concerns a press for operating an electrical terminal applicator.
2. Description of Related Prior Art
There is described in each U.S. Pat. No. 3,400,625 and U.S. Pat. No. 4,024,807, a press having a press ram which is driven in sliding reciprocating movement by an electric motor through a drive shaft rotatably supported in a press frame and having a pair of annular members thereon which are eccentric with respect to the axis of rotation of the drive shaft, each annular member being mounted for rotation in bearings in a respective bearing block which is received in a transverse guideway in a respective cross head of the ram. As the drive shaft is rotated by means of the motor, each bearing block moves along the guideway and thereby takes up the eccentricity of the annular member. U.S. Pat. No. 3,064,559 and U.S. Pat. No. 4,761,988 disclose analogous eccentric means for driving a press ram, in which an annular eccentric member of the drive shaft of the press is mounted in a roller bearing ring. Further analogous eccentric means for driving a press ram are disclosed in JP-A-55-48500, AT-A-253360 and AT-A-245939, the ram being mounted at the forward end of the press frame (in the case of the two latter of these references) and being driven by a single eccentric member and bearing block arrangement. DD-A-132707 discloses a press having a ram which is vertically slidable on inner and outer bearing tracks, the outer tracks being adjustable with respect to the inner tracks for adjusting the desired bearing resistance. According to U.S. Pat. No. 4,024,807, each of said cross heads has a central axis which is perpendicular to the axis of rotation of the drive shaft and is parallel to the guideway, each cross head being mounted to slide into bearings which are bisected by the central axis of the cross head.
According to U.S. Pat. Nos. 4,024,807, 3,400,625, 3,064,559 the electric motor drives the drive shaft connected to the eccentric means, by way of a belt and pully speed reduction means. In each case the rotational axis of the motor which is mounted outside of the press, is offset from the drive shaft and the speed reduction means is located at an end of the press housing remote from the ram.
De-A-3320023 discloses a press comprising a direct current electric motor connected to a slide ram of the press by way of reduction gearing and an eccentric drive shaft, and a control circuit arrangement comprising an incremental encoder for producing a first output representing the angular position of the drive shaft, and thus the linear position of the slide ram and means for controlling the speed of the drive motor to stop the slide ram at least proximate to a home position thereof at the end of each cycle of operation of the slide ram. This control circuit arrangement does not continuously monitor the speed of the motor so that the ram is not stopped proximate to its home position until several cycles of the press have been carried out.